* fix(responses): Presidio PII masking for Azure WebSocket and streaming
Wire Presidio into native Responses WebSocket forwarding and fix streaming output unmasking so masked tokens are restored for HTTP and WS clients.
Co-authored-by: Cursor <cursoragent@cursor.com>
* Fix unused imports in responses handlers
* fix(responses): address Greptile review - Azure WebSocket model URL and PII logging
- Add model_in_websocket_url() to BaseResponsesAPIConfig (default True) so
providers can opt out of ?model= being appended to WebSocket URLs.
- Override model_in_websocket_url() to return False for Azure, since Azure
sends the model in the response.create body, not the URL query string.
- Use this flag in llm_http_handler to conditionally append ?model=.
- Pass masked message to _store_input() instead of the original PII-containing
message so logging destinations do not receive unmasked PII.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* fix(responses): mask nested response.create input format for Presidio PII
Handle the nested {"type":"response.create","response":{"input":[...]}}
format in _mask_response_create. Previously only the flat top-level input
was masked; the nested shape bypassed Presidio and forwarded raw PII
upstream. Now both shapes are normalized and masked before forwarding.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* style: apply black formatting to llm_http_handler and streaming_iterator
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* style: suppress PLR0915 on async_responses_websocket
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* fix(responses): add apply_to_output masking on Responses API WebSocket path
Previously the WebSocket guardrail filter excluded callbacks with
apply_to_output=True, leaving model-generated PII unmasked before
returning to the client.
- Collect apply_to_output callbacks separately in llm_http_handler and
pass them to ResponsesWebSocketStreaming as output_guardrail_callbacks.
- Add _mask_response_completed method that calls check_pii(output_parse_pii=False)
on text blocks in response.completed events, masking model output PII.
- backend_to_client now chains unmask (pii_tokens) → mask (apply_to_output)
before forwarding each event to the client.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* fix(responses): unmask PII tokens in streaming delta events and warn on guardrail init failure
- Rename _unmask_response_completed -> _unmask_response_event and extend
it to also unmask response.output_text.delta (and other delta types)
so real-time streaming clients receive original values, not PII tokens.
- Split the broad except-and-swallow into ImportError (expected in SDK-only
environments) vs Exception (unexpected — now logs a warning so operators
know masking is disabled).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* fix(responses): enforce authorized model on WebSocket frames and remove proxy import
Security: add _enforce_authorized_model to ResponsesWebSocketStreaming that
overwrites both flat and nested model fields in every response.create frame
with the connection-authorized model, preventing deployment-substitution
attacks where an authenticated user sends a different model name in the frame
body after connecting with an allowed model.
Layering: remove the _OPTIONAL_PresidioPIIMasking isinstance check and proxy
import from the SDK handler. Use duck-typed checks (callable check_pii +
get_presidio_settings_from_request_data) so any guardrail implementing the
interface works, not just Presidio.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* fix(responses): add _unmask_pii_text to duck-typed contract and mask delta frames
- Add callable(_unmask_pii_text) check to the guardrail_callbacks filter so
a custom guardrail missing that method cannot cause an AttributeError and
silently kill the WebSocket session.
- Extend _mask_response_completed to also mask response.output_text.delta
(and other delta types) for apply_to_output callbacks, so real-time
streaming clients do not receive unredacted model-generated PII in deltas.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* Fix Responses WebSocket guardrail edge cases
* fix(responses): log masked output and suppress deltas when apply_to_output active
- Move _store_event to after _mask_response_completed so logs receive the
redacted form, not raw model output containing PII.
- Suppress delta event forwarding when output_guardrail_callbacks are
present: per-fragment Presidio cannot catch PII that spans multiple
chunks (e.g. "alice@" + "example.com"). Clients receive only the
fully-masked response.completed, which Presidio scans on complete text.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* fix(responses): mask and suppress response.output_item.done for apply_to_output
response.output_item.done carries completed item text in item.content[*].text
before response.completed arrives, allowing unmasked PII to reach the client.
- _unmask_response_event: unmask input-PII tokens in item.content[*].text
- _mask_response_completed: run check_pii on item.content[*].text for
apply_to_output callbacks (same as response.completed handling)
- backend_to_client suppression: also skip response.output_item.done when
output_guardrail_callbacks are active; client receives only the
fully-masked response.completed
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* fix(types): cast response_obj to ResponsesAPIResponse to satisfy mypy
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* Revert "fix(types): cast response_obj to ResponsesAPIResponse to satisfy mypy"
This reverts commit d5969557628f9aff58948b9d37cc64d577f95a15.
* Revert "fix(responses): mask and suppress response.output_item.done for apply_to_output"
This reverts commit 219fd54ea3446f4399fde40c07ba0617e2834573.
* fix(types): accept dict responses in guardrail output write-back
Streaming response.completed events pass a dict response object, so widen
_apply_guardrail_responses_to_output to match its existing runtime handling.
Co-authored-by: Cursor <cursoragent@cursor.com>
* perf(responses): skip Presidio masking on suppressed WebSocket delta events
Delta events are dropped wholesale when apply_to_output masking is active,
so masking them first issued a wasted check_pii call per fragment. Move the
suppression check ahead of the unmask/mask passes; the event type is
invariant across both, so client-visible behavior is unchanged.
* test(responses): cover Responses WebSocket PII masking hooks
Add regression tests for the native Responses WebSocket guardrail path:
input masking and model enforcement in _mask_response_create, token
unmasking in _unmask_response_event, apply_to_output masking and delta
suppression in _mask_response_completed/backend_to_client, and the
get_websocket_url / model_in_websocket_url defaults for the base and
Azure configs. Raises diff coverage above the codecov patch target.
* fix(responses): suppress text-bearing done events under output PII masking
When apply_to_output masking is active on a native Responses WebSocket,
response.output_text.done, response.content_part.done, and
response.output_item.done carry the full model output before the masked
response.completed arrives, so an authenticated client could read
unmasked PII from those events. Suppress them alongside delta events; the
client receives only the fully-masked response.completed.
* refactor(responses): drop dead delta branch in WebSocket output masking
Delta events are suppressed in backend_to_client before _mask_response_completed
runs when output masking is active, so the method's delta-handling branch was
unreachable. Restrict it to response.completed and cover the Responses API
unmask path with a Pydantic ResponseCompletedEvent regression test.
* fix(presidio): flush buffered chat chunks on mixed unmask stream
_stream_pii_unmasking buffered ModelResponseStream chunks but returned
early once a /v1/responses event was seen, silently dropping the buffered
chat chunks. Flush them in order before switching to passthrough, mirroring
_stream_apply_output_masking, and cover it with a regression test.
* fix(responses): mask instructions and tool-call arguments in WebSocket PII path
Presidio masking on the native Responses WebSocket path left two gaps. On the
request side _mask_response_create only walked the input containers, so PII
placed in the instructions field of a response.create frame was forwarded
upstream and logged unmasked even with output_parse_pii enabled. Now both the
flat and nested instructions strings are masked alongside input.
On the response side _mask_response_completed only masked content text blocks,
so model-produced PII inside function-call arguments could reach the client when
apply_to_output was enabled, both via the standalone
response.function_call_arguments.done event and via the function_call output
items in response.completed. The done event is now suppressed under output
masking and completed function-call arguments are run through check_pii before
forwarding or logging.
* fix(responses): suppress reasoning_summary_text.done under output PII masking
* fix(responses): mask function_call_output.output in WebSocket PII path
response.create input items of type function_call_output carry
user-controlled text in output, not content, so the Presidio masking
pass forwarded that text upstream unmasked. Mask the output field
(string or list of text blocks) alongside content.
* fix(responses): mask reasoning summary PII in WebSocket output path
---------
Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-authored-by: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
|
||
|---|---|---|
| .circleci | ||
| .devcontainer | ||
| .githooks | ||
| .github | ||
| .semgrep/rules | ||
| backend | ||
| ci_cd | ||
| cookbook | ||
| db_scripts | ||
| deploy | ||
| dist | ||
| docker | ||
| docs | ||
| enterprise | ||
| gateway | ||
| helm/litellm | ||
| litellm | ||
| litellm-proxy-extras | ||
| migrations | ||
| packaging/homebrew | ||
| scripts | ||
| terraform/litellm | ||
| tests | ||
| ui | ||
| .dockerignore | ||
| .env.example | ||
| .flake8 | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitguardian.yaml | ||
| .gitignore | ||
| .npmrc | ||
| AGENTS.md | ||
| ARCHITECTURE.md | ||
| CLAUDE.md | ||
| codecov.yaml | ||
| CONTRIBUTING.md | ||
| cosign.pub | ||
| docker-compose.hardened.yml | ||
| docker-compose.yml | ||
| Dockerfile | ||
| GEMINI.md | ||
| LICENSE | ||
| license_cache.json | ||
| Makefile | ||
| mcp_servers.json | ||
| model_prices_and_context_window.json | ||
| package-lock.json | ||
| package.json | ||
| policy_templates.json | ||
| prometheus.yml | ||
| provider_endpoints_support.json | ||
| proxy_server_config.yaml | ||
| pyproject.toml | ||
| pyrightconfig.json | ||
| README.md | ||
| render.yaml | ||
| ruff.toml | ||
| schema.prisma | ||
| security.md | ||
| taplo.toml | ||
| uv.lock | ||
🚅 LiteLLM
LiteLLM AI Gateway
Open Source AI Gateway for 100+ LLMs. Self-hosted. Enterprise-ready. Call any LLM in OpenAI format.
LiteLLM Proxy Server (AI Gateway) | Hosted Proxy | Enterprise Tier | Website
What is LiteLLM
LiteLLM is an open source AI Gateway that gives you a single, unified interface to call 100+ LLM providers — OpenAI, Anthropic, Gemini, Bedrock, Azure, and more — using the OpenAI format.
Use it as a Python SDK for direct library integration, or deploy the AI Gateway (Proxy Server) as a centralized service for your team or organization.
Jump to LiteLLM Proxy (LLM Gateway) Docs
Jump to Supported LLM Providers
Why LiteLLM
Managing LLM calls across providers gets complicated fast — different SDKs, auth patterns, request formats, and error types for every model. LiteLLM removes that friction:
- Unified API — one interface for 100+ LLMs, no provider-specific SDK juggling
- Drop-in OpenAI compatibility — swap providers without rewriting your code
- Production-ready gateway — virtual keys, spend tracking, guardrails, load balancing, and an admin dashboard out of the box
- 8ms P95 latency at 1k RPS (benchmarks)
OSS Adopters
Netflix |
Features
LLMs - Call 100+ LLMs (Python SDK + AI Gateway)
All Supported Endpoints - /chat/completions, /responses, /embeddings, /images, /audio, /batches, /rerank, /a2a, /messages and more.
Python SDK
uv add litellm
from litellm import completion
import os
os.environ["OPENAI_API_KEY"] = "your-openai-key"
os.environ["ANTHROPIC_API_KEY"] = "your-anthropic-key"
# OpenAI
response = completion(model="openai/gpt-4o", messages=[{"role": "user", "content": "Hello!"}])
# Anthropic
response = completion(model="anthropic/claude-sonnet-4-20250514", messages=[{"role": "user", "content": "Hello!"}])
AI Gateway (Proxy Server)
Getting Started - E2E Tutorial - Setup virtual keys, make your first request
uv tool install 'litellm[proxy]'
litellm --model gpt-4o
import openai
client = openai.OpenAI(api_key="anything", base_url="http://0.0.0.0:4000")
response = client.chat.completions.create(
model="gpt-4o",
messages=[{"role": "user", "content": "Hello!"}]
)
Agents - Invoke A2A Agents (Python SDK + AI Gateway)
Supported Providers - LangGraph, Vertex AI Agent Engine, Azure AI Foundry, Bedrock AgentCore, Pydantic AI
Python SDK - A2A Protocol
from litellm.a2a_protocol import A2AClient
from a2a.types import SendMessageRequest, MessageSendParams
from uuid import uuid4
client = A2AClient(base_url="http://localhost:10001")
request = SendMessageRequest(
id=str(uuid4()),
params=MessageSendParams(
message={
"role": "user",
"parts": [{"kind": "text", "text": "Hello!"}],
"messageId": uuid4().hex,
}
)
)
response = await client.send_message(request)
AI Gateway (Proxy Server)
Step 1. Add your Agent to the AI Gateway
Step 2. Call Agent via A2A SDK
from a2a.client import A2ACardResolver, A2AClient
from a2a.types import MessageSendParams, SendMessageRequest
from uuid import uuid4
import httpx
base_url = "http://localhost:4000/a2a/my-agent" # LiteLLM proxy + agent name
headers = {"Authorization": "Bearer sk-1234"} # LiteLLM Virtual Key
async with httpx.AsyncClient(headers=headers) as httpx_client:
resolver = A2ACardResolver(httpx_client=httpx_client, base_url=base_url)
agent_card = await resolver.get_agent_card()
client = A2AClient(httpx_client=httpx_client, agent_card=agent_card)
request = SendMessageRequest(
id=str(uuid4()),
params=MessageSendParams(
message={
"role": "user",
"parts": [{"kind": "text", "text": "Hello!"}],
"messageId": uuid4().hex,
}
)
)
response = await client.send_message(request)
MCP Tools - Connect MCP servers to any LLM (Python SDK + AI Gateway)
Python SDK - MCP Bridge
from mcp import ClientSession, StdioServerParameters
from mcp.client.stdio import stdio_client
from litellm import experimental_mcp_client
import litellm
server_params = StdioServerParameters(command="python", args=["mcp_server.py"])
async with stdio_client(server_params) as (read, write):
async with ClientSession(read, write) as session:
await session.initialize()
# Load MCP tools in OpenAI format
tools = await experimental_mcp_client.load_mcp_tools(session=session, format="openai")
# Use with any LiteLLM model
response = await litellm.acompletion(
model="gpt-4o",
messages=[{"role": "user", "content": "What's 3 + 5?"}],
tools=tools
)
AI Gateway - MCP Gateway
Step 1. Add your MCP Server to the AI Gateway
Step 2. Call MCP tools via /chat/completions
curl -X POST 'http://0.0.0.0:4000/v1/chat/completions' \
-H 'Authorization: Bearer sk-1234' \
-H 'Content-Type: application/json' \
-d '{
"model": "gpt-4o",
"messages": [{"role": "user", "content": "Summarize the latest open PR"}],
"tools": [{
"type": "mcp",
"server_url": "litellm_proxy/mcp/github",
"server_label": "github_mcp",
"require_approval": "never"
}]
}'
Use with Cursor IDE
{
"mcpServers": {
"LiteLLM": {
"url": "http://localhost:4000/mcp/",
"headers": {
"x-litellm-api-key": "Bearer sk-1234"
}
}
}
}
Supported Providers (Website Supported Models | Docs)
Get Started
You can use LiteLLM through either the Proxy Server or Python SDK. Both give you a unified interface to access multiple LLMs (100+ LLMs). Choose the option that best fits your needs:
| LiteLLM AI Gateway | LiteLLM Python SDK | |
|---|---|---|
| Use Case | Central service (LLM Gateway) to access multiple LLMs | Use LiteLLM directly in your Python code |
| Who Uses It? | Gen AI Enablement / ML Platform Teams | Developers building LLM projects |
| Key Features | Centralized API gateway with authentication and authorization, multi-tenant cost tracking and spend management per project/user, per-project customization (logging, guardrails, caching), virtual keys for secure access control, admin dashboard UI for monitoring and management | Direct Python library integration in your codebase, Router with retry/fallback logic across multiple deployments (e.g. Azure/OpenAI) - Router, application-level load balancing and cost tracking, exception handling with OpenAI-compatible errors, observability callbacks (Lunary, MLflow, Langfuse, etc.) |
Stable Release: Use docker images with the -stable tag. These have undergone 12 hour load tests, before being published. More information about the release cycle here
Support for more providers. Missing a provider or LLM Platform, raise a feature request.
Run in Developer Mode
Services
- Setup .env file in root
- Run dependent services
docker-compose up db prometheus
Backend
- (In root) create virtual environment
python -m venv .venv - Activate virtual environment
source .venv/bin/activate - Install dependencies
uv sync --all-extras --group proxy-dev uv run prisma generateprisma generate- Start proxy backend
python litellm/proxy/proxy_cli.py
Frontend
- Navigate to
ui/litellm-dashboard - Install dependencies
npm install - Run
npm run devto start the dashboard
Verify Docker Image Signatures
All LiteLLM Docker images published to GHCR are signed with cosign. Every release is signed with the same key introduced in commit 0112e53.
Verify using the pinned commit hash (recommended):
A commit hash is cryptographically immutable, so this is the strongest way to ensure you are using the original signing key:
cosign verify \
--key https://raw.githubusercontent.com/BerriAI/litellm/0112e53046018d726492c814b3644b7d376029d0/cosign.pub \
ghcr.io/berriai/litellm:<release-tag>
Verify using a release tag (convenience):
Tags are protected in this repository and resolve to the same key. This option is easier to read but relies on tag protection rules:
cosign verify \
--key https://raw.githubusercontent.com/BerriAI/litellm/<release-tag>/cosign.pub \
ghcr.io/berriai/litellm:<release-tag>
Replace <release-tag> with the version you are deploying (e.g. v1.83.0-stable).
Enterprise
For companies that need better security, user management and professional support
Get an Enterprise License Talk to founders
This covers:
- ✅ Features under the LiteLLM Commercial License:
- ✅ Feature Prioritization
- ✅ Custom Integrations
- ✅ Professional Support - Dedicated discord + slack
- ✅ Custom SLAs
- ✅ Secure access with Single Sign-On
Contributing
We welcome contributions to LiteLLM! Whether you're fixing bugs, adding features, or improving documentation, we appreciate your help.
Quick Start for Contributors
This requires uv to be installed.
git clone https://github.com/BerriAI/litellm.git
cd litellm
make install-dev # Install development dependencies
make format # Format your code
make lint # Run all linting checks
make test-unit # Run unit tests
make format-check # Check formatting only
For detailed contributing guidelines, see CONTRIBUTING.md.
📖 Contributing to documentation? The LiteLLM docs have moved to a separate repository: BerriAI/litellm-docs. Please open doc PRs there. Docs are served at docs.litellm.ai.
Code Quality / Linting
LiteLLM follows the Google Python Style Guide.
Our automated checks include:
- Black for code formatting
- Ruff for linting and code quality
- MyPy for type checking
- Circular import detection
- Import safety checks
All these checks must pass before your PR can be merged.
Support / talk with founders
- Schedule Demo 👋
- Community Discord 💭
- Community Slack 💭
- Our emails ✉️ ishaan@berri.ai / krrish@berri.ai